injector size question within
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,009
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From: Springfield MO
injector size question within
according to my datamaster my duty cycle spike to 85% at WOT and then climbs to 95% as high rpms are sustained. Yet my O2s genereally ready in the low 900's except during shift points. Should I go on up to a 30# or call it good with the stockers?
Melting Slicks
Joined: Apr 2001
Posts: 2,117
Likes: 221
From: Ca.
Re: injector size question within (AS84)
according to my datamaster my duty cycle spike to 85% at WOT and then climbs to 95% as high rpms are sustained. Yet my O2s genereally ready in the low 900's except during shift points. Should I go on up to a 30# or call it good with the stockers?
Just to double check....so at 6000rpm the inj. pulse width is up to 9.5 sec?
Then in that case-YES! Go with a bigger inj! Of course you'll have to reprogram for them, but I sure wouldn't just call it good by looking at the o2 of low 900's!!! After using a wide band for awhile now I've found that you just cannot use the narrow band mv to figure your wot f/a ratio's-mine was reading 950 on the narrow band at wot-then made a run with the wide band and it was at 13.8 to 14.0!!!!
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: injector size question within (AS84)
You might want to consider larger injectors. The stock injector design is supposed to be good to 85% max. Above that they are supposed to flutter and overheat. Its a good idea to keep a safe margin instead of running to the absolute limit for things like injectors that control fuel flow. Consider that you don't run your fuel tank to almost absolute empty for obvious reasons.
You could go with Ford Motorsport 24 lbs which is about 26 lb at 43 psi or 30 lb units which flow 31.5 lbs. The price is the same and 30 lbs is not so large that it causes idle problems.
You could go with Ford Motorsport 24 lbs which is about 26 lb at 43 psi or 30 lb units which flow 31.5 lbs. The price is the same and 30 lbs is not so large that it causes idle problems.
Melting Slicks
Joined: Sep 2000
Posts: 3,099
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From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: injector size question within (AquaMetallic94LT1)
no you do not need bigger injectors at 900 you are a liitle rich go to a track run your 900 then turn down pressure to get to 830-840 and watch it pick up i only have 24lb fms and i am running low 11s in the quater remember that is a batch injection those 22lb are fireing twice per cycle so they are really like 44lb injectors the lt1 guys are secuential so they are really running what they have
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,009
Likes: 1
From: Springfield MO
Re: injector size question within (CORKVETTE1)
The pulse width will ready as high as 11.5 after high rpms are sustained. With 36 degrees of total timing I rarely see knock counts, so I don't think I'm running overly lean.
